The Skype for Business App SDK has been retired and is not available for download and use. Instead, we recommend Azure Communication Services, where we will continue to invest our development resources.
Migrating to Azure Communication Services
Azure Communication Services is a cloud-based communications service that lets you add voice, video, chat, and telephony to your apps. ACS applications have the ability to join Teams meetings (as a guest), and we encourage implementers of the SfB App SDK to transition to Azure Communication Services. The ability to join Teams meetings as a guest using ACS is now available.
Azure SDKs that join Teams meetings
Azure Communication Services has multiple SDKs that can join Teams meetings listed below.